Vehicle inspection system

ABSTRACT

The present invention discloses a vehicle inspection system, comprising: a radiation source; 
     an inspection passage enabling a vehicle to pass; a dragging system comprising a first dragging means and a second dragging means, which are sequentially arranged along a vehicle dragging direction; in the vehicle dragging direction, the first dragging means is arranged at the upstream of the second dragging means, and a separating section is arranged between the first dragging means and the second dragging means, so that the first dragging means is separated from the second dragging means by a preset distance in the vehicle dragging direction; and the first and second dragging means both include a supporting plate, an elongated traction element and a pushing element connected with the elongated traction element, the elongated traction elements of the first and second dragging means are continuous and integrated, thus the elongated traction elements and pushing elements extends on the separating section; the supporting plates of the first and second dragging means are separated and two pieces type, and no supporting plate is provided on the separating section.

This application claims priority to Chinese Patent Application No.201410418956.3, filed on Aug. 22, 2014, which is hereby incorporated byreference in its entirety.

FIELD OF INVENTION

The present invention relates to a vehicle inspection system.

BACKGROUND OF INVENTION

In a top-irradiation type vehicle inspection system, a radiation sourceis provided on the top of an inspection passage, a detector is providedon the bottom of the inspection passage. The inspected vehicle istypically driven to advance by chain type dragging means. The draggingmeans includes plate like carrier frame on the bottom, chain and pushingroller on the frame. In the power of motor, the inspected vehicle ismoved by means of chain and pushing roller. Since supporting plates ofthe carrier frame is a metal structural, thus shielding ray beams whenthe vehicle is inspected. Consequently, the detector fails to obtainsingles and meanwhile the obtained image is black, which severelyinfluences the image quality and the inspection effect.

SUMMARY OF INVENTION

The objection of the present invention is to provide a vehicleinspection system, in order to ease or eliminate influence of draggingequipment on a scanned image.

According to one aspect of the present invention, a vehicle inspectionsystem comprising: a radiation source; an inspection passage enabling avehicle to pass; a dragging system comprising a first dragging means anda second dragging means, which are sequentially arranged along a vehicledragging direction; in the vehicle dragging direction, the firstdragging means is arranged at the upstream of the second dragging means,and a separating section is arranged between the first dragging meansand the second dragging means, so that the first dragging means isseparated from the second dragging means by a preset distance in thevehicle dragging direction; and the first and second dragging means bothinclude a supporting plate, an elongated traction element and a pushingelement connected with the elongated traction element, the elongatedtraction elements of the first and second dragging means are continuousand integrated, thus the elongated traction elements and pushingelements extends on the separating section; the supporting plates of thefirst and second dragging means are separated and two pieces type, andno supporting plate is provided on the separating section.

According to one aspect of the present invention, the invention providesa vehicle inspection system, comprising: a radiation source forproviding X-ray beams for scanning a vehicle; a detector used forreceiving the X-ray beams emitted from the radiation source; aninspection passage for enabling the vehicle to pass, wherein a scanningmeans frame is arranged within the range of the inspection passage, theradiation source is arranged at the top of the scanning means frame forscanning the vehicle passing the inspection passage, and the detector isarranged at a position opposite to the radiation source; a draggingsystem comprising a first dragging means and a second dragging means,which are sequentially arranged along a vehicle dragging direction; inthe vehicle dragging direction, the first dragging means is arranged atthe upstream of the second dragging means, and a separating section isarranged between the first dragging means and the second dragging means,so that the first dragging means is separated from the second draggingmeans by a preset distance in the vehicle dragging direction; and atleast a part of paths of the beams of the radiation source passesthrough the separating section between the first dragging means and thesecond dragging means; the first and second dragging means both includea supporting plate, an elongated traction element and a pushing elementconnected with the elongated traction element, the elongated tractionelements of the first and second dragging means are continuous andintegrated, thus the elongated traction elements and pushing elementsextends on the separating section; the supporting plates of the firstand second dragging means are separated and two pieces type, and nosupporting plate is provided on the separating section.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising: the dragging means is arranged on the groundat one side within the range of the inspection passage, and is able todrag the vehicle driving into the inspection passage to pass theinspection passage.

According to one aspect of the present invention, the width of theinspection passage is arranged in such a manner that the vehicle is ableto pass the inspection passage by means of the dragging means, and thevehicle is also able to pass the inspection passage along the groundprovided with no dragging means.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising: radiation shield walls arranged at the twosides of the inspection passage, a pedestrian passage arranged behindthe radiation shield walls, for enabling a driver to walk from astarting point where the vehicle drives into the inspection passage tothe destination where the vehicle is about to leave the inspectionpassage.

According to one aspect of the present invention, a vehicle inspectionsystem, comprising: an inspection passage, a dragging system arranged inthe inspection passage; and a radiographic inspection system forinspecting a vehicle, wherein the radiographic inspection systemcomprises a radiation source for emitting beams and a detector forreceiving the beams emitted by the radiation source and penetratingthrough the inspected vehicle; a dragging system comprising a firstdragging means and a second dragging means, which are sequentiallyarranged along a vehicle dragging direction; in the vehicle draggingdirection, the first dragging means is arranged at the upstream of thesecond dragging means, and a separating section is arranged between thefirst dragging means and the second dragging means, so that the firstdragging means is separated from the second dragging means by a presetdistance in the vehicle dragging direction; and at least a part of pathsof the beams of the radiographic inspection system passes through theseparating section between the first dragging means and the seconddragging means; the first and second dragging means both include asupporting plate, a elongated traction element and a pushing elementconnected with the elongated traction element, the elongated tractionelements of the first and second dragging means are continuous andintegrated, thus the elongated traction elements and pushing elementsextends on the separating section; the supporting plates of the firstand second dragging means are separated and two pieces type, and nosupporting plate is provided on the separating section.

According to one aspect of the present invention, the pushing element isused for pushing wheels to move so as to drive the vehicle to advance.

According to one aspect of the present invention, the radiation sourceis arranged above the inspection passage.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising a driving passage arranged in the inspectionpassage and used for enabling the vehicle to voluntarily pass, whereinthe driving passage is arranged to be substantially parallel to thedragging means.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising a controller, wherein the controller correctsan acquired image of the inspected vehicle according to a scanned imageacquired by the vehicle inspection system during no load of the draggingmeans, in order to remove the image of the dragging means from theacquired image of the inspected vehicle.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising a controller, wherein the controller correctsan acquired image of the inspected vehicle according to a scanned imageacquired by the vehicle inspection system during no load of the draggingmeans, in order to remove the image of at least one of the elongatedtraction element and the pushing element from the acquired image of theinspected vehicle.

According to one aspect of the present invention, the controllercorrects the acquired image of the inspected vehicle according to theposition relationship of the inspected vehicle and at least one of theelongated traction element and the pushing element along the vehicletransfer direction, in order to remove the image of at least one of theelongated traction element and the pushing element from the acquiredimage of the inspected vehicle.

According to one aspect of the present invention, the pushing element ofthe dragging means contacts the wheels of the vehicle and pushes thewheels, in order to determine the position relationship of the inspectedvehicle and at least one of the elongated traction element and thepushing element along the vehicle transfer direction.

According to one aspect of the present invention, the vehicle inspectionsystem further comprising: a position detecting means for detectingwhether the pushing element arrives at a preset position, and sending asignal to the controller when the pushing element pushing the wheels ofthe vehicle or the pushing element during no load of the dragging meansarrives at the preset position, in order to start the radiographicinspection system to scan the vehicle or the no-load dragging means.

According to one aspect of the present invention, the position detectingmeans is an optical transceiver, the optical transceiver is arranged atone side of the dragging means and emits a light beam towards one sideof the dragging means, when the light beam irradiates a reflector at theend part of the pushing element, the optical transceiver receives thelight beam reflected by the reflector at the end part of the pushingelement, in order to determine that the pushing element arrives at thepreset position.

According to one aspect of the present invention, the first draggingmeans comprises a first elongated traction element and a first pushingelement connected with the first elongated traction element, and thefirst pushing element is adapted to push the wheels to move so as todrive the vehicle to advance; the second dragging means comprises asecond elongated traction element and a second pushing element connectedwith the second elongated traction element, and the second pushingelement is adapted to push the wheels to move so as to drive the vehicleto advance.

According to one aspect of the present invention, the vehicle passes theinspection passage under a first mode, a second mode or a third mode,under the first mode, the vehicle voluntarily passes the inspectionpassage, and the radiographic inspection system does not inspect thevehicle, under the second mode, the vehicle voluntarily passes theinspection passage, and the radiographic inspection system inspects thevehicle by adopting a dosage lower than a first preset value, and underthe third mode, the dragging system drags the vehicle to pass theinspection passage, and the radiographic inspection system inspects thevehicle by adopting a dosage larger than or equal to a second presetvalue.

According to one aspect of the present invention, under the first modeand the second mode, the wheels of at least one side of the vehicledrive on the first dragging means and the second dragging means or thevehicle drives on a road beside the first dragging means and the seconddragging means.

According to one aspect of the present invention, the pushing element isadapted to push the wheels to move so as to drive the vehicle toadvance, the vehicle inspection system further comprises a drivingpassage arranged in the inspection passage and used for enabling thevehicle to voluntarily pass, and the driving passage is arranged to besubstantially parallel to the dragging means, and under the first mode,the vehicle voluntarily passes the inspection passage.

According to one aspect of the present invention, the vehicle inspectionsystem is integrated with a highway charging card interface.

According to one aspect of the present invention, the elongated tractionelement is a chain or a plate link chain.

The vehicle inspection system according to the embodiments of thepresent invention can be used for easing or eliminating the influence ofthe dragging equipment on the scanned image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an embodiment of an inspection systemaccording to an embodiment of the present invention;

FIG. 2 is a top view of an embodiment of an inspection system accordingto the present invention;

FIG. 3 is a schematic diagram of a vehicle inspection system accordingto an embodiment of the present invention, wherein a vehicle draggingsystem includes two dragging means;

FIG. 4 is a schematic diagram of a vehicle inspection system accordingto another embodiment of the present invention, wherein a vehicledragging system includes two dragging means;

FIG. 5 is a schematic diagram of measurement by twice photographing;

FIG. 6 is a position diagram when a pushing element, e.g., a rollercontacts a wheel;

FIG. 7 is a speed-time curve of a pushing element, e.g., a roller;

FIG. 8 is a schematic diagram of a vehicle inspection system accordingto another embodiment of the present invention, wherein a vehicledragging system includes two dragging means;

FIG. 9 is a schematic diagram of controlling a pushing element accordingto another embodiment of the present invention;

FIG. 10 is a schematic diagram of a speed-time curve of a pushingelement, e.g., a roller;

FIG. 11 is a schematic diagram of a vehicle inspection system adopting aCT system according to another embodiment of the present invention,wherein a vehicle dragging system includes two dragging means;

FIG. 12 is a schematic diagram of a pushing element of a vehicleinspection system according to an embodiment of the present invention,wherein the pushing element is provided with a detecting means used fordetecting whether the pushing element contacts a wheel of a vehicle anda feedback means;

FIG. 13 is a schematic diagram of a pushing element of a vehicleinspection system according to an embodiment of the present invention,wherein a position detecting means used for detecting whether thepushing element arrives at a preset position is shown;

FIG. 14 is a schematic top view of a vehicle dragging system of avehicle inspection system according to an embodiment of the presentinvention, wherein a dragging means of the vehicle dragging systemincludes a plate link chain;

FIG. 15 is a schematic side view of a vehicle dragging system of avehicle inspection system according to an embodiment of the presentinvention, wherein a dragging means of the vehicle dragging systemincludes a plate link chain;

FIG. 16 is a schematic side view of a vehicle inspection systemaccording to an embodiment of the present invention;

FIG. 17 is a schematic top view of a vehicle inspection system accordingto an embodiment of the present invention;

FIG. 18 is a schematic front view of a vehicle inspection systemaccording to an embodiment of the present invention, wherein a radiationsource arranged at one of the left side and the right side of aninspection passage is shown;

FIG. 19 is a schematic front view of a vehicle inspection systemaccording to an embodiment of the present invention, wherein a radiationsource arranged above an inspection passage is shown;

FIG. 20 is a schematic diagram of a structure of a plate link chain of adragging means of a vehicle dragging system of a vehicle inspectionsystem according to an embodiment of the present invention, wherein (A)is a front view and (B) is a top view;

FIG. 21 is a schematic top view of a vehicle dragging system of avehicle inspection system according to an embodiment of the presentinvention, wherein a dragging means of the vehicle dragging systemincludes a pushing roller; and

FIG. 22 is a schematic side view of a vehicle dragging system of avehicle inspection system according to an embodiment of the presentinvention, wherein a dragging means of the vehicle dragging systemincludes a pushing roller.

DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiment 1

As shown in FIG. 1, a vehicle inspection system according to anembodiment of the present invention includes: an inspection passage 101,a vehicle dragging system 100 and a radiographic inspection system 151.

As shown in FIG. 2, the vehicle dragging system 100 includes a firstdragging means 111 and a second dragging means 112, which aresequentially arranged along a vehicle dragging direction E, wherein inthe vehicle dragging direction E, the first dragging means 111 isarranged at the upstream of the second dragging means 112, and aseparating section 113 is arranged between the first dragging means 111and the second dragging means 112, for separating the first draggingmeans 111 from the second dragging means 112 at a preset distance in thevehicle dragging direction E. The first dragging means 111 and thesecond dragging means 112 are arranged in the inspection passage 101. Atleast a part of the paths of the beams of the radiographic inspectionsystem 151 penetrates through the separating section 113 between thefirst dragging means 111 and the second dragging means 112.

In some embodiments of the present invention, as shown in FIG. 1 andFIG. 2, the radiographic inspection system 151 includes a radiationsource 152 arranged at one of the upper side and the lower side of theseparating section 113 between the first dragging means 111 and thesecond dragging means 112, and a detector 153 at least partiallyarranged at the other one of the upper side and the lower side of theseparating section 113 between the first dragging means 111 and thesecond dragging means 112 and used for receiving beams emitted by theradiation source 152 and penetrating through the inspected vehicle. Theradiation source 152 can be an X radiation source or other suitableradiation sources.

For example, as shown in FIG. 1 and FIG. 2, radiation shield walls 70are arranged at the two sides of the inspection passage 101, a scanningmeans framework 80 is arranged within the range of the inspectionpassage 101, the radiation source 152 is arranged at the top of thescanning means framework 80 for scanning the vehicle passing theinspection passage 101, and the detector 153 is arranged under theground corresponding to the radiation source 152.

In some embodiments of the present invention, as shown in FIG. 11, theradiographic inspection system 151 may include a slip ring 154, aradiation source 152 installed on the slip 154, and a detector 153installed on the slip ring 154, wherein the detector 153 is used forreceiving the beams emitted by the radiation source 152 and penetratingthrough the inspected vehicle. The slip ring 154 is driven by a drivingmechanism to rotate, in order to drive the radiation source 152 and thedetector 153 to rotate around the vehicle.

As shown in FIG. 14, FIG. 15, FIG. 20, FIG. 21 and FIG. 22, the firstdragging means 111 includes a first supporting plate 1111, a first chain114 (an example of an elongated traction element) and a first pushingelement 1141 connected with the first chain 114, and the first pushingelement 1141 moves around the first supporting plate 1111 for pushingwheels to move along the first supporting plate 1111, in order to drivea vehicle to advance. The second dragging means 112 includes a secondsupporting plate 1121, a second chain 114 (an example of the elongatedtraction element) and a second pushing element 1141 connected with thesecond chain 114, and the second pushing element 1141 moves around thesecond supporting plate 1121 for pushing the wheels to move along thesecond supporting plate 1121, in order to drive the vehicle to advance.

See FIG. 3, FIG. 7, FIG. 8, FIG. 9, FIG. 10 and FIG. 11, the vehicledragging system further includes a controller (not shown), wherein thecontroller controls the first pushing element 1141 to push a first wheelof the vehicle at a first speed, when a second wheel of the vehiclearrives at a preset position A of the second dragging means 112 awayfrom the separating section 113 at a preset distance, the second chain114 moves, thus the second pushing element 1141 at the lower side of thesecond supporting plate 1121 moves to contact the second wheel of thevehicle at a second speed and push the second wheel of the vehicle, inorder to keep the moving state of the vehicle, and in the vehicledragging direction E, the second wheel is located at the downstream sideof the first wheel. The second speed may be larger than or equal to thefirst speed, and the second speed and the first speed may be basicallyconstant. Before the first pushing element 1141 is separated from thefirst wheel, the second pushing element 1141 contacts the second wheel.

As shown in FIG. 3, the vehicle dragging system further includes asensor 118 used for sending a signal when the second wheel of thevehicle arrives at the preset position A, and the sensor 118 is locatedat the preset position A of the second dragging means 112 away from theseparating section 113 for the preset distance. After receiving thesignal of the sensor 118, the controller allows the second chain 114 toperform accelerated motion, and allows the second pushing element 1141located at the lower side of the second supporting plate 1121 to movefor a preset time, touch the second wheel of the vehicle at the secondspeed and push the second wheel of the vehicle. The sensor 118 can be apressure sensor, a photoelectric sensor or a piezoelectric sensor or thelike, and the pressure sensor, the photoelectric sensor or thepiezoelectric sensor or the like is arranged at the preset position A ofthe second dragging means 112.

For example, as shown in FIG. 3, the vehicle moves from left to right,the pushing element 1141 of the first dragging means 111 pushes the rearwheel of the vehicle, in order to allow the vehicle to move rightwardsat a first speed V. When the front wheel of the vehicle arrives at thesensor 117 arranged at the preset position D, the pushing element 1141on the second dragging means 112 stops at an S point.

According to an embodiment of the present invention, when the frontwheel of the vehicle arrives at the preset position A, after receivingthe signal of the sensor 118, the controller allows the second chain 114to perform accelerated motion and then decelerate to the second speed.The accelerated motion can be uniformly accelerated motion, and thedecelerated motion can be uniformly decelerated motion(

). The pushing element 1141 of the second dragging means 112 performsaccelerated motion and accelerates to a speed V2 (V2>V), keeps the speedV2 and then pushes the front wheel of the vehicle to move. Preferably,when the moving speed of the vehicle becomes the speed V2, the beamemission frequency of an X-ray beams generating means 3 (or the stretchfactor of a local image) is changed. For example, the ratio of thevehicle speed to the beam emission frequency is constant. Preferably,the system adopts a speed measuring means to track the speed of thevehicle when moving from the first dragging means 111 to the seconddragging means 112 and is driven on the second dragging means 112, andwhen the vehicle speed changes, the beam emission frequency of the X-raybeams generating means 3 is changed. The accelerated motion of thepushing element 1141 can be uniformly accelerated motion.

In the embodiment as shown in FIG. 1, the radiation source 152 includesthe X-ray beams generating means 3 and a beam collimator 4, and the beamemission range of beams is shown by a dotted line as shown by referencesign 5. According to a preferable embodiment of the present invention,the beam generating means includes an electronic linear accelerator(e.g., a 1.5 MeV electronic linear accelerator) or an X-ray beamsmachine. Preferably, the width of the inspection passage 101 is 3.5 mand the height thereof is 4 m. Correspondingly, the width of the top ofthe vehicle capable of being inspected by the vehicle inspection systemdisclosed by the present invention is not larger than 1.8 m, the widthof the bottom of the vehicle is not larger than 2.4 m and the height isnot larger than 2 m. Preferably, as shown in FIG. 1, the X-ray beamsgenerating means 3 is arranged at the top of the scanning meansframework 80, and the beam collimator 4 is arranged at the lower side.When the vehicle drives into the inspection passage 101 and enters themain beam range 5 of the beams, the vehicle is scanned by X-ray beams,and the detector 153 arranged underground receives the X-ray beams.Preferably, the detector 153 adopted herein is a 5 mm×2.5 mm cadmiumtungstate array detector, which acquires an overlooking image of thevehicle through vertical transmission imaging technology. Preferably,the scanning speed is 0.1 m/s or 0.2 m/s.

The inspected vehicle can be a small vehicle, for example, the vehiclecan be a passenger car or a coach.

The above-mentioned specific arrangement parameters and selected meansare merely used for exemplarily illustrating the solutions of thepresent invention, rather than limiting the technical solutions of thepresent invention, those skilled in the art can select other parametersand means according to actual demands, and these variations ormedications are all within the protection scope of the presentinvention.

As shown in FIG. 1, the vehicle inspection system disclosed by thepresent invention can be integrated with a highway toll station toperform security inspection work of important transportation hubs,reference sign 81 expresses safety islands at the two sides of theinspection passage, and the safety islands 81 can be seen more clearlyin FIG. 2. The vehicle inspection system disclosed by the presentinvention can also be applied to places in fields such as importantbuildings, important activity areas or land border ports or the like, toperform security inspection work.

According to the preferable embodiment of the present invention, thefirst dragging means 111 and the second dragging means 112 are arrangedat one side in the inspection passage 101 and can drag the vehicledriving into the inspection passage 101 to pass the inspection passage101. The first dragging means 111 pushes the rear wheels of the vehicle,and then the second dragging means 112 pushes the front wheels of thevehicle, thus the separating section 113 is arranged between the firstdragging means 111 and the second dragging means 112. The path of thebeams from the radiation source 152 to the detector 153 passes theseparating section 113, in order to avoid the influence of the firstdragging means 111 and the second dragging means 112 on a scanned image.

According to some embodiments of the present invention, the width of theinspection passage 101 is arranged in such a manner that the vehicle canpass the inspection passage 101 through the vehicle dragging system 100,and meanwhile, the vehicle can pass the inspection passage 101 along theground with no dragging means.

Specifically, see FIG. 2, the direction E is the vehicle travellingdirection. According to the preferable embodiment of the presentinvention, the condition that the vehicle in dotted lines is dragged tothe exit of the inspection passage 101 by the vehicle dragging system100, security inspection is performed on the vehicle, under thecondition, an unmanned mode is adopted, a driver leaves the vehicle atthe starting point where the vehicle 6 enters the first dragging means111, and walks to the destination of the second dragging means 112through a passage 10 to wait for the vehicle after inspection. Thepassage 10 is arranged at the rear side of the radiation shield walls70, in order to prevent the driver of suffering from radiation of theX-ray beams. FIG. 2 also shows another condition, namely, the vehicle isnot dragged by the vehicle dragging system 100, but the driver quicklydrives over the inspection passage 101, and the inspection system canselect to scan the vehicle by adopting a radiation dosage safe for thedriver, or select to not scan the vehicle. In other words, according tothe technical solutions provided by the present invention, the vehiclepasses the inspection passage 101 in one of the above-mentioned threemanners. Namely, different vehicles can be classified, the vehiclesneeding no security inspection can pass without being dragged by thevehicle dragging system 100, and are driven to quickly pass theinspection passage 101; the vehicles with low security risk may be notdragged by the vehicle dragging system 100 and are scanned at a lowradiation dosage when quickly passing the inspection passage 101; thevehicles with high security risk are dragged by the vehicle draggingsystem 100 to pass the inspection passage 101 for scanning at a standardradiation dosage, in this way, the security inspection workingefficiency can be greatly improved and traffic jams are improved.

Preferably, a single dragging means herein can be a dragging means inthe car washer industry, namely, a single side wheel dragging means,since the dragging means has been commonly applied in the car washingindustry, it can be introduced into the vehicle security inspectionfield as mature technology, such that repeated research and developmenton a vehicle moving means are avoided. The dragging means is mostlabor-saving, energy-saving and environmental-friendly; a truckle onlycontacts the wheels, thus generating the minimum wear and collision onvehicles, as a result, it is easy to be accepted by owners and drivers.

Besides the above-mentioned advantages, the vehicle inspection systemprovided by the present invention can be directly built on the safetyisland of an existing toll station, thus the civil engineering workloadis small and the floor space is small. Furthermore, being similar to asmall luggage X-ray beams security inspection machine, when the vehiclepasses an X ray beam flow surface, a scanned image is automaticallyacquired in real time, thus the security inspection efficiency andaccuracy are greatly improved.

FIG. 3 shows a schematic diagram of a vehicle inspection systemincluding the first dragging means 111 and the second dragging means112. The separating section 113 is arranged between the first draggingmeans 111 and the second dragging means 112, and beams 5 penetratethrough the separating section to irradiate the detector 153.

Preferably, as shown in FIG. 2 and FIG. 3, the separating section 113between the first dragging means 111 and the second dragging means 112is provided with a platform 12, which is convenient for the vehicle totravel on the separating section 113 between the first dragging means111 and the second dragging means 112. The upper surface of the platform12 and the ground plane in the inspection passage are in the sameheight. A gap 115 can be formed at the middle of the platform 12, inorder to prevent the beams from the collimator 4 to the detector 153from being shielded to truly realize non-shielded scanning of the entiredragging means.

The gap 115 may be formed in the separating section 113.

Alternatively, one material with the same thicknesses as that of the gapcan be arranged in the gap 115 of the platform 12 to improve the sealingproperty of the system. This nearly generates no influence on thescanned image, because the one material with the thickness would adduniform backgrounds on the image. Of course, the materials are selectedby comprehensively considering beam penetrability loss, physicalstrength and price of materials, for example, aluminum, iron, plasticand carbon fiber and other materials.

As shown in FIG. 3, an overturning plate 13 facilitates passage ofvehicle wheels and allows the pushing element 1141 on the seconddragging means 112 to pass, and the overturning plate 13 can rotatearound a pivot. The pivot is perpendicular to the extension direction ofthe second dragging means 112 or the direction E.

Embodiment 2

A scanned vehicle passes a scanning area at a constant speed, which willbring great inconvenience to scanning control and data processing, andthe purpose of the embodiment is to enable the vehicle to pass theseparating section 113 between the first dragging means 111 and thesecond dragging means 112 at the constant speed.

The structure of the system in the embodiment is as shown in FIG. 1 andFIG. 2 as well, and the dragging means is as shown in FIG. 4. The maindifference between FIG. 4 and FIG. 3 lies in that an image acquiringmeans 14 is arranged at one side (adjacent to the first dragging means111) of the inspection passage 101 and is located near the presetposition D.

As shown in FIG. 4, the vehicle dragging system further includes asensor 118 used for sending a signal when the second wheel of thevehicle arrives at the preset position A, and the sensor 118 is locatedat the preset position A of the second dragging means 112 away from theseparating section 113 for the preset distance. After receiving thesignal from the sensor 118, the controller allows the second chain 114to perform accelerated motion, and allows the second pushing element1141 located at the lower side of the second supporting plate 1121 tomove for a preset time, contact the second wheel of the vehicle at thesecond speed and push the second wheel of the vehicle. The sensor 118can be a pressure sensor, a photoelectric sensor or a piezoelectricsensor or the like, and the pressure sensor, the photoelectric sensor orthe piezoelectric sensor or the like is arranged at the preset positionA of the second dragging means 112.

As shown in FIG. 4, the vehicle dragging system further includes a wheeldiameter acquiring means used for measuring the diameter of the secondwheel of the vehicle, and a calculating means, wherein the calculatingmeans is used for calculating a travelling distance necessary for thesecond pushing element 1141 to catch up with the second wheel andcontact the second wheel, according to the diameter of the second wheelacquired by the vehicle diameter acquiring means and the position of thesecond pushing element 1141 located at the lower side of the secondsupporting plate 1121. The wheel diameter acquiring means can include animage acquiring means, and the image acquiring means is used foracquiring two images including the second wheel at a preset timeinterval, and calculating the diameter of the second wheel of thevehicle according to the vehicle displacement distances in the twoimages, the first speed of the vehicle, the diameters of the secondwheel of the vehicle in the images and the time interval. The imageacquiring means can be a camera or video camera 14, is arranged at thepreset position D of the first dragging means 111 away from theseparating section 113 by a preset distance and is located at one sideof the first dragging means 111.

For example, as shown in FIG. 4, the vehicle moves from left to right,the pushing element 1141 of the first dragging means 111 pushes the rearwheel of the vehicle, in order to allow the vehicle to move rightwardsat the first speed V. When the front wheel of the vehicle arrives at thesensor 117 arranged at the preset position D (ground), the pushingelement 1141 on the second dragging means 112 stops at the S point, andthe camera or video camera 14 is started to shoot the vehicle. After ashort time interval t, the vehicle is shot again. The camera or videocamera 14 can clearly shoot the front wheel of the vehicle and thenearby area thereof.

As shown in FIG. 5, the camera or video camera 14 shoots a photograph ofthe inspected vehicle and shoots a photograph again at a time intervalt. The vehicle moves at the speed V, and the vehicle advances a distanceVt within the time t. The outside diameter of the front wheel of thevehicle is measured on the photograph, and the vehicle moving distancesare measured on two photographs, in this way, two measurements can bemanually performed on the photographs, and can also be automaticallyprocessed by use of an image processing algorithm. The outside diameterof the front wheel of the vehicle:

$\begin{matrix}{{2\; R} = {{Vt} \times \frac{\begin{matrix}{{{outside}\mspace{14mu} {diameter}\mspace{14mu} {of}\mspace{14mu} {front}}\mspace{11mu}} \\{{wheel}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{20mu} {on}\mspace{14mu} {the}\mspace{14mu} {photograph}}\end{matrix}}{{staggered}\mspace{14mu} {distance}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{14mu} {on}\mspace{14mu} {two}\mspace{14mu} {photographes}}}} & (1)\end{matrix}$

In this way, the outside diameter of the front wheel of the vehicle canbe measured, and the measurement of the outside diameter of the frontwheel is very important for the second pushing element 1141 on thesecond dragging means 112 to contact the wheel of the vehicle at apreset speed. Of course, under the condition that the outside diameterof the front wheel is known, the travelling speed can be measured inreturn. Alternatively, under the condition that the outside diameter ofthe front wheel and the travelling speed are known, the time interval ismeasured by the technology. The method is liable to expand to variousfields, such as size measurement, speed measurement, time measurementand the like, and the measurement object is not limited to vehicles orwheels. In addition, the purpose of improving the precision can berealized by improving the measurement precision of each parameter,selecting multiple data measurement points or shooting for multipletimes.

Of course, vehicle type identification or other methods for measuringthe diameter of the front wheel can replace the above-mentioned shootingmeasurement method to complete the step of measuring the diameter of thefront wheel in the present invention. However, the shooting measurementmethod has the advantages of low cost, mature equipment technology,saving occupation area and the like.

As shown in FIG. 6, under the condition that the pushing element 1141 isa roller, after the diameter of the front wheel is measured, when thepushing element 1141 of the second dragging means 112 pushes the frontwheel, the relative distance a therebetween can be accuratelycalculated. If the diameter 2R of the front wheel and the radius r ofthe pushing element 1141 are known, it can be obtained that

a=√{square root over ((R+r)²−(R−r)²)}{square root over((R+r)²−(R−r)²)}=2√{square root over (Rr)}  (2)

For example, when the front wheel of the vehicle arrives at the sensor118 at the preset position A, the pushing element 1141 of the seconddragging means 112 performs accelerated motion and accelerates to aspeed V3 (V3>V), gradually decelerates to the speed V and then pushesthe front wheel of the vehicle to move. The motion rate-timerelationship of the pushing element 1141 of the second dragging means112 is preferably as shown in FIG. 7 (A). The pushing element 1141accelerates to the speed V3 from a static state after a time t1 and thendecelerates to V after a time t2. As shown in FIG. 4, the distance fromthe S to the position A is L. The pushing element 1141 chases the frontwheel and needs to travel a distance L-a more than the vehicle. Thepushing element 1141 moves according to the rate-time curve as shown inFIG. 7,

L−a=0.5×[V3×t1+(V3+V)×t2]−V×(t1+t2)  (3)

V3, t1 and t2 can be flexibly designed according to demand, but beforethe rear wheel arrives at the platform 12 as shown in FIG. 4, thepushing element 1141 must catch up with the front wheel at the speed V.By the way, the measurement of L can be calculated by the accurate sizeof the second dragging means 112 and can also be deduced according tothe time interval of the pushing element 1141 for passing through theposition S and the position A at a constant speed, and can be used as aparameter of the system.

Preferably, the accelerated motion and decelerated motion of the pushingelement 1141 are uniformly accelerated motion and uniformly deceleratedmotion.

Obviously, the pushing element 1141 can chase the front wheel accordingto other rate-time curves, for example, according to FIG. 7 (B). Whenthe front wheel of the vehicle arrives at the preset position A, thepushing element 1141 accelerates to the speed V3, constantly advances atthe speed V3 and then decelerates to V and catches up with the frontwheel of the vehicle. According to the forgoing manner, a kinematicformula can be obtained, and will not be repeated herein. Actually,according to the properties of a motor and by adopting a specificrate-time curve, various chasing manners can be designed, includingvariable acceleration chasing, as long as the chasing distance L-a isobtained.

In the solution of the embodiment, the moving speed of the vehicle iskept to V, and the beam emission frequency of the X-ray beams generatingmeans 3 is not necessarily changed, so that the beam emission anddetection system control complexity is reduced.

Embodiment 3

In the embodiment 2, it is realized that the vehicle passes theseparating section 113 at the constant speed and the dragging means doesnot shield the scanning beams. The method for measuring the outsidediameter of the wheel is also provided. But the system is slightlycomplicated, including that the distance L as shown in FIG. 4 needs tobe measured. In the embodiment 3, based on the measurement of theoutside diameter of the wheel, the vehicle is kept to move at theconstant speed, and the L value does not need to be measured.

Compared with the embodiment 2, the major modification in systemdeployment is as follows: the image acquiring means 14 is changed fromthe preset position D to a position near the preset position A and isadjacent to one side of the dragging means, as shown in FIG. 8.

As shown in FIG. 8, the vehicle dragging system further includes adistance acquiring apparatus used for measuring the distance between thesecond wheel of the vehicle and the second pushing element 1141, whenthe second wheel of the vehicle arrives at the preset position A of thesecond dragging means 112 away from the separating section 113 for thepreset distance, the distance acquiring apparatus acquires the distancebetween the second wheel and the second pushing element 1141 to serve asthe travelling distance necessary for the second pushing element 1141 tocatch up with the second wheel and contact the second wheel.

See FIG. 8, the distance acquiring apparatus may include an imageacquiring means, wherein the image acquiring means 14 is used foracquiring two images including the second wheel and the second pushingelement 1141 at a preset time interval, and calculating the distancebetween the second wheel and the second pushing element 1141 accordingto the vehicle displacement distances in the two images, the distancebetween the second wheel and the second pushing element 1141, the firstspeed of the vehicle and the time interval. The image acquiring meansmay be a camera or video camera, can be arranged at the preset positionA of the second dragging means 112 away from the separating section 113for the preset distance and is located at one side of the seconddragging means 112.

In this way, the image acquiring means can be not only used foracquiring the diameter of the second wheel of the vehicle, but also usedfor acquiring the distance between the second wheel and the secondpushing element 1141, and the distance is the foundation for calculatingthe travelling distance necessary for the second pushing element 1141 tocatch up with the second wheel and contact the second wheel. It is notdifficult to understand that an accurate chasing distance should beacquired by subtracting the distance in the vehicle traveling directionof the second wheel and the second pushing element when the second wheelcontacts the second pushing element from the distance (for such circularpushing elements as a pushing roller, it is a in the formula 2).

As shown in FIG. 8, the vehicle dragging system further includes asensor 118 used for sending a signal when the second wheel of thevehicle arrives at the preset position A away from the separatingsection 113 for the preset distance of the second dragging means 112,after receiving the signal of the sensor 118, the controller operatesthe distance acquiring apparatus to acquire the distance between thesecond wheel and the second pushing element 1141. The sensor 118 can bea pressure sensor, a photoelectric sensor or a piezoelectric sensor orthe like, and the pressure sensor, the photoelectric sensor or thepiezoelectric sensor or the like is arranged at the preset position A ofthe second dragging means 112.

Preferably, as shown in FIG. 8, the vehicle moves from left to right,the pushing element 1141 of the first dragging means 111 pushes the rearwheel of the vehicle, in order to allow the vehicle to move rightwardsat the first speed V. When the front wheel of the vehicle arrives at thefirst sensor 117 arranged at the preset position D, the pushing element1141 on the second dragging means 112 stops at the S point and begins tostart to a speed V4 (V4>V). When the front wheel of the vehicle arrivesat the second sensor 118 (the photoelectric sensor or the piezoelectricsensor) at the second preset position A, the vehicle and the front wheelthereof are shot, as shown in FIG. 9A. When the pushing element 1141 onthe second dragging means 112 arrives at the second sensor 118 at thepreset position A, the vehicle and the front wheel thereof are shotagain, as shown in FIG. 9B. A system timer (not shown) records the timeinterval t′ of twice shooting. Similar to the foregoing principle ofmeasuring the outside diameter 2R of the front wheel, it is easy toacquire:

$\begin{matrix}{{2R} = {{Vt}^{\; \prime} \times \frac{{outside}\mspace{14mu} {diameter}\mspace{14mu} {of}\mspace{14mu} {front}\mspace{14mu} {wheel}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{20mu} {on}\mspace{14mu} {photographs}}{{staggered}\mspace{14mu} {distance}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{14mu} {on}\mspace{14mu} {two}\mspace{14mu} {photographs}}}} & (4)\end{matrix}$

during the second time shooting, the distance between the pushingelement 1141 and the front wheel of the vehicle is measured on thephotograph as well. Then, the actual distance b between the pushingelement 1141 and the front wheel of the vehicle satisfies a formula:

$\begin{matrix}{b = {{Vt}^{\; \prime} \times \frac{\begin{matrix}{{distance}\mspace{14mu} {between}\mspace{14mu} {front}\mspace{14mu} {wheel}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{11mu} {and}} \\{{pushing}\mspace{14mu} {element}\mspace{14mu} {on}\mspace{14mu} {the}\mspace{14mu} {photographs}}\end{matrix}}{{staggered}\mspace{14mu} {distance}\mspace{14mu} {of}\mspace{14mu} {vehicle}\mspace{14mu} {on}\mspace{14mu} {two}\mspace{14mu} {photographs}}}} & (5)\end{matrix}$

wherein the pushing element 1141 needs to chase for a distance b-a tocatch up with the front wheel of the vehicle (a is acquired bysubstituting R calculated in formula 4 into the formula 2).

When the pushing element 1141 arrives at the preset position A, thepushing element 1141 begins to uniformly decelerate to the speed V aftera time t3 and catches up with the front wheel of the vehicle (as shownin FIG. 9C), the speed-time curve is as shown in FIG. 10A, it can beknown that:

b−a=0.5×(V4−V)t3  (6)

the acceleration is equal to

p=(V−V4)/t3  (7)

Beginning from the front wheel arrives at the preset position A untilthe pushing element 1141 catches up with the front wheel, the movingdistance of the vehicle is equal to V (t′+t3). As shown in FIG. 8, thespace from the edge of the first dragging means 111 to the presetposition A is g. In order to ensure that before the first pushingelement 1141 of the first dragging means 111 is separated from the firstwheel (e.g., the rear wheel), the second pushing element 1141 of thesecond dragging means 112 contacts the second wheel (e.g., the frontwheel), it is assumed that the minimum value of the space between thefront and rear wheels of all common vehicles is equal to M, then

V(t′+t3)+g<M  (8)

and this condition should be satisfied in system design.

System parameters and control parameters are designed according to theformulas 6-8: the acceleration p, the speed V4, the time intervals t′,t3, and intermediate calculation is completed by the formulas 4-5.Therefore, the vehicle can stably pass the separating section 113 at theconstant speed.

Of course, the speed-time curve of the pushing element 1141 can bechanged from FIG. 10A into FIG. 10B, namely, after arriving at thepreset position A, the pushing element 1141 continues to travel a timet4 at the constant speed, then uniformly decelerates to the speed Vafter a time t5 and catches up with the front wheel of the vehicle. Thismanner facilitates accelerating the chasing progress. Additional timeparameter is adjustable, thus increasing the design flexibility of thesystem. Of course, the solution is a little more complicated to becontrolled than the solution as shown in FIG. 10A. Actually, the pushingelement 1141 can chase the front wheel according to various speed-timecurves, including variable accelerated motion, as long as it issatisfied that the speed of the pushing element 1141 is equal to thespeed of the vehicle, when the pushing element catches up with the frontwheel.

In the embodiment, the positioning of the preset position D and thepreset position S is not necessarily very accurate, thus the system costcan be further reduced.

As shown in FIG. 8, in order to enable the vehicle to stably pass theseparating section 113 between the first dragging means 111 and thesecond dragging means 112, a pedal 15 can be arranged in the system.When the front wheel arrives at the preset position D, the pedal 15 isstretched out to enable the front wheel to stably pass. The pedal 15 isretracted after the front wheel passes. Of course, the pedal 15 can beomitted under the condition that the requirement on the stabletravelling of the vehicle is not particularly high or the diameter ofthe pushing element 1141 is small enough.

Actually, by means of the speed-time curve and the technology of thepresent invention, the vehicle pushing speeds of the first draggingmeans 111 and the second dragging means 112 can be randomly controlled,so as to meet a variety of application demands.

Embodiment 4

The dragging system in the foregoing embodiments 1, 2 and 3 are appliedto a perspective scanning imaging system to achieve no shielding tobeams. As mentioned above, the radiographic inspection system in thepresent invention can include a CT scanning system, as shown in FIG. 11.The radiation source 152 and the detector 153 are installed on the slipring 154. The dragging system in the present invention can also beapplied to a nuclear magnetic resonance imaging system, to avoid theinfluence of the dragging means on imaging.

As shown in FIG. 12, the vehicle dragging system further includes asensor 81, wherein the sensor 81 is arranged on the second pushingelement 1141 and is used for detecting whether the second pushingelement 1141 has been in contact with the second wheel (e.g., the frontwheel) of the vehicle. The sensor can be a contact sensor, a pressuresensor, a piezoelectric sensor or the like. The vehicle dragging systemfurther includes a feedback means 82. The sensor detects whether thesecond pushing element 1141 has been in contact with the front wheel andnotifies the controller of the vehicle inspection system through theconnected feedback means 82. After receiving the signal that the secondpushing element 1141 has been in contact with the second wheel (e.g.,the front wheel) of the vehicle, the controller of the vehicleinspection system can control the second dragging means 112 to push thevehicle to advance at a pushing speed larger than that of the firstdragging means 111. As another alternative preferable solution, afterreceiving the signal that the second pushing element 1141 has been incontact with the second wheel (e.g., the front wheel) of the vehicle,the vehicle inspection system can control the second dragging means 112to push the vehicle to advance at a pushing speed equal to the pushingspeed of the first dragging means 111, namely, dragging the vehicle at aconstant speed. Apparently, in the solution, the image acquiring means14 as shown in FIG. 8 can be omitted, and even the sensor 117 at thepreset position D and the sensor 118 at the preset position A as shownin FIG. 8 are omitted.

Preferably, the sensor 81 is a piezoelectric sensor. Preferably, thefeedback means includes a radio signal emitting unit used for sendingthe signal to the controller of the vehicle inspection system.

According to the vehicle inspection system provided by the presentinvention, the vehicle inspection system can be integrated with ahighway toll station to perform online quick security inspection onvehicles; the radiation shield walls are arranged to avoid accidentalradiation on pedestrians or drivers; the dragging means can be used fordragging the vehicles to pass the inspection passage 101 under anunmanned condition, and small vehicles can voluntarily and quickly passthe inspection passage 101 without using the dragging means, such thatdifferent vehicles can be processed in a classification manner, which isbeneficial to easing traffic jam.

In this way, the scanned image can be acquired by the beams in anon-shielding manner when the vehicle is dragged or driven to pass theinspection passage.

Embodiment 5

As shown in FIG. 1, the vehicle inspection system according to theembodiment of the present invention includes an inspection passage 101for enabling a vehicle to pass, a vehicle dragging system 100 arrangedin the inspection passage 101 and a radiographic inspection system 151used for inspecting the vehicle.

As shown in FIG. 1 and FIG. 2, the radiographic inspection system 151includes a radiation source 152 used for emitting beams, for example,providing X-ray beams for scanning the vehicle; and a detector 153 usedfor receiving the beams emitted by the radiation source and penetratingthrough the inspected vehicle, for example, used for receiving the X-raybeams emitted by the radiation source 152. Radiation shield walls 70 arearranged at the two sides of the inspection passage 101, a scanningmeans framework 80 is arranged within the range of the inspectionpassage 101, and the radiation source 152 is arranged above theinspection passage 101. For example, the radiation source 152 isarranged at the top of the scanning means framework 80, in order to scanthe vehicle passing the inspection passage 101, and the detector 153 isarranged at a position opposite to the radiation source 152.

The vehicle dragging system 100 includes dragging means 111, 112, andthe dragging means 111, 112 are arranged on the ground at one sidewithin the range of the inspection passage 101 and can drag the vehicledriving into the inspection passage 101 to pass the inspection passage101.

It should be noted that, in the embodiment, the vehicle dragging system100 may include one or two dragging means.

The width of the inspection passage 101 is arranged in such a mannerthat the vehicle can pass the inspection passage 101 through thedragging means, and meanwhile, the vehicle can pass the inspectionpassage 101 along the ground provided with no dragging means. Namely, atravelling passage for enabling the vehicle to voluntarily pass isarranged in the inspection passage 101, and the travelling passage isarranged to be substantially parallel to the dragging means.

The vehicle inspection system further includes a pedestrian passage,wherein the pedestrian passage is arranged at the rear of the radiationshield walls 70, for allowing a driver to walk from a starting pointwhere the vehicle is driven into the inspection passage 101 to thedestination where the vehicle is about to leave the inspection passage101.

See FIG. 14, FIG. 20, FIG. 21 and FIG. 22, each of the dragging means111, 112 includes a chain 114 and a pushing element 1141 connected withthe chain 114, and the pushing element 1141 is used for pushing wheelsto move, in order to drive the vehicle to advance. The pushing element1141 of the dragging means can merely push the left wheels or the rightwheels of the vehicle.

According to some embodiments of the present invention, the firstsupporting plate 1111 and second supporting plate 1121 are separated atthe separating section 113 and are two pieces type, and no supportingplate is provided on the separating section 113. The first and secondchains 114 are continuous and integrated. Chains 114 and pushing member1141 continuously extend on the first dragging means 111, the separatingsection 113 and the second dragging means 112. The vehicle inspectionsystem further includes a controller, wherein the controller corrects anacquired image of the inspected vehicle according to a scanned imageacquired by the vehicle inspection system during no load of the draggingmeans, in order to remove the image of the dragging means from theacquired image of the inspected vehicle, for example, the controllercorrects the acquired image of the inspected vehicle according to thescanned image acquired by the vehicle inspection system during no loadof the dragging means, in order to remove the image of at least one ofthe chain and the pushing element from the acquired image of theinspected vehicle. The controller can correct the acquired image of theinspected vehicle according to the position relationship of theinspected vehicle and at least one of the chain and the pushing elementalong the vehicle travelling direction, in order to remove the image ofat least one of the chain and the pushing element from the acquiredimage of the inspected vehicle.

According to some embodiments of the present invention, the pushingelement of the dragging means contacts the wheels of the vehicle andpushes the wheels, in order to determine the position relationship ofthe inspected vehicle and at least one of the chain and the pushingelement along the vehicle travelling direction.

As shown in FIG. 13, the vehicle inspection system further includes aposition detecting means 119 used for detecting whether the pushingelement 1141 arrives at a preset position, and sending a signal to thecontroller when the pushing element pushing the wheels of the vehicle orthe pushing element during no load of the dragging means arrives at thepreset position, in order to start the radiographic inspection system toscan the vehicle or the no-load dragging means. The position detectingmeans 1141 can be an optical transceiver, the optical transceiver isarranged at one side of the dragging means and emits a light beamtowards one side of the dragging means, and when the light beamirradiates a reflector 120 at the end of the pushing element 1141, theoptical transceiver receives the light beam reflected by the reflector120 at the end of the pushing element 1141, and thus determines that thepushing element 1141 arrives at the preset position.

Under the condition that the vehicle dragging system includes twodragging means, as shown in FIG. 2, the vehicle dragging system 100includes a first dragging means 111 and a second dragging means 112,which are sequentially arranged along a vehicle dragging direction E, inthe vehicle dragging direction, the first dragging means 111 is arrangedat the upstream of the second dragging means 112, and a separatingsection 113 is arranged between the first dragging means 111 and thesecond dragging means 112, for enabling the first dragging means 111 andthe second dragging means 112 to be separated at a preset distance inthe vehicle dragging direction E. The first dragging means 111 and thesecond dragging means 112 are arranged in the inspection passage 101. Atleast a part of paths of the beams of the radiographic inspection system151 passes through the separating section 113 between the first draggingmeans 111 and the second dragging means 112. As shown in FIG. 14, FIG.15, FIG. 20, FIG. 21 and FIG. 22, the first dragging means 111 includesa first supporting plate 1111, a first chain 114 and a first pushingelement 1141 connected with the first chain 114, and the first pushingelement 1141 moves around the first supporting plate 1111 for pushingwheels to move along the first supporting plate 1111, in order to drivea vehicle to advance. The second dragging means 112 includes a secondsupporting plate 1121, a second chain 114 and a second pushing element1141 connected with the second chain 114, and the second pushing element1141 moves around the second supporting plate 1121 for pushing thewheels to move along the second supporting plate 1121, in order to drivethe vehicle to advance.

In the vehicle inspection system according to the embodiment of thepresent invention, the vehicle can pass the inspection passage 101 undera first mode, a second mode or a third mode, under the first mode, thevehicle voluntarily passes the inspection passage 101, and theradiographic inspection system does not inspect the vehicle; under thesecond mode, the vehicle voluntarily passes the inspection passage 101,and the radiographic inspection system inspects the vehicle by adoptinga dosage lower than a first preset value, wherein the dosage of thefirst preset value can be a maximal dosage harmless to human body andcan also be a certain dosage below the maximal dosage; and under thethird mode, the vehicle dragging system drags the vehicle to pass theinspection passage 101, and the radiographic inspection system inspectsthe vehicle by adopting a dosage larger than or equal to a second presetvalue, the second preset value can be the same as or different from thefirst preset value, and preferably, the second preset value is largerthan the first preset value.

Under the first mode and the second mode, the wheels on at least oneside of the vehicle drive on the first dragging means and the seconddragging means, or the vehicle drives on a road beside the firstdragging means and the second dragging means. As mentioned above, thevehicle inspection system further includes a travelling passage arrangedin the inspection passage 101 and used for enabling the vehicle tovoluntarily pass, the travelling passage is arranged to be substantiallyparallel to the dragging means, and under the first mode, the vehiclevoluntarily drives over the travelling passage.

According to some embodiments, the vehicle can be a passenger car or acoach. The vehicle inspection system can be integrated with a highwaycharging card interface.

According to the embodiment of the present invention, the separatingsection 113 can be arranged between the first dragging means 111 and thesecond dragging means 112 to avoid the interference of the draggingmeans on the beams, or the acquired image of the inspected vehicle iscorrected to remove the image of at least one of the chain and thepushing element from the acquired image of the inspected vehicle, so asto acquire an accurate image of the inspected vehicle. In addition,according to the embodiment of the present invention, the images ofother (static or moving) components of the dragging means or the imagesof other (static or moving) components of the vehicle dragging system orthe vehicle inspection system can also be removed from the acquiredimage of the inspected vehicle.

Embodiment 6

As shown in FIG. 1, the vehicle inspection system according to theembodiment of the present invention includes an inspection passage 101,a vehicle dragging system 100 arranged in the inspection passage and aradiographic inspection system 151.

As shown in FIG. 2, the vehicle dragging system 100 includes a firstdragging means 111 and a second dragging means 112, which aresequentially arranged along a vehicle dragging direction E, wherein inthe vehicle dragging direction, the first dragging means 111 is arrangedat the upstream of the second dragging means 112, and a separatingsection 113 is arranged between the first dragging means 111 and thesecond dragging means 112, for enabling the first dragging means 111 andthe second dragging means 112 to be separated at a preset distance inthe vehicle dragging direction. The first dragging means 111 and thesecond dragging means 112 are arranged in the inspection passage 101. Atleast a part of paths of the beams of the radiographic inspection system151 passes through the separating section 113 between the first draggingmeans 111 and the second dragging means 112. As shown in FIG. 14, a beamflow center 106 is located on the separating section 113.

In some embodiments of the present invention, as shown in FIG. 1 andFIG. 2, the radiographic inspection system 151 includes a radiationsource 152 arranged at one of the upper side and the lower side of theseparating section 113 between the first dragging means 111 and thesecond dragging means 112, and a detector 153 at least partiallyarranged at the other one of the upper side and the lower side of theseparating section 113 between the first dragging means 111 and thesecond dragging means 112 and used for receiving beams emitted by theradiation source 152 and penetrating through the inspected vehicle. Theradiation source 152 can be an X radiation source.

As shown in FIG. 14, FIG. 15, FIG. 20, FIG. 21 and FIG. 22, the firstdragging means 111 includes a first supporting plate 1111, a first chain114 and a first pushing element 1141 connected with the first chain 114,and the first pushing element 1141 moves around the first supportingplate 1111 for pushing wheels to move along the first supporting plate1111, in order to drive a vehicle to advance. The second dragging means112 includes a second supporting plate 1121, a second chain 114 and asecond pushing element 1141 connected with the second chain 114, and thesecond pushing element 1141 moves around the second supporting plate1121 for pushing the wheels to move along the second supporting plate1121, in order to drive the vehicle to advance.

See FIG. 16, FIG. 17, FIG. 18 and FIG. 19, the radiographic inspectionsystem includes:

a first radiation source 1521 arranged at one of the upper side and thelower side of the separating section 113 between the first draggingmeans 111 and the second dragging means 112, and a first detector 1531at least partially arranged at the other one of the upper side and thelower side of the separating section 113 between the first draggingmeans 111 and the second dragging means 112 and used for receiving beamsemitted by the first radiation source 1521 and penetrating through theinspected vehicle; and

a second radiation source 1522 arranged at one side, in a transversedirection substantially perpendicular to an up and down direction andthe vehicle dragging direction E, of the separating section 113 betweenthe first dragging means 111 and the second dragging means 112, and asecond detector 1532 at least partially arranged at the other side inthe transverse direction of the separating section 113 between the firstdragging means 111 and the second dragging means 112 and used forreceiving beams emitted by the second radiation source 1522 andpenetrating through the inspected vehicle. The first radiation source1521 and the second radiation source 1522 are X-ray beams acceleratorsor X-ray beams machines, or one of the first radiation source 1521 andthe second radiation source 1522 is an X-ray beams accelerator, and theother one of the first radiation source 1521 and the second radiationsource 1522 is an X-ray beams machine.

Alternatively, see FIG. 16, FIG. 17, FIG. 18 and FIG. 19, theradiographic inspection system includes:

a first radiation source 1521 arranged at one of the upper side and thelower side of the separating section 113 between the first draggingmeans 111 and the second dragging means 112, and a first detector 1531at least partially arranged at the other one of the upper side and thelower side of the separating section 113 between the first draggingmeans 111 and the second dragging means 112 and used for receiving beamsemitted by the first radiation source 1521 and penetrating through theinspected vehicle, wherein the first radiation source 1521 is an X-raybeams accelerator or an X-ray beams machine, and/or

the radiographic inspection system includes:

a second radiation source 1522 arranged at one side, in a transversedirection substantially perpendicular to an up and down direction andthe vehicle dragging direction E, of the separating section 113 betweenthe first dragging means 111 and the second dragging means 112, and asecond detector 1532 at least partially arranged at the other side inthe transverse direction of the separating section 113 between the firstdragging means 111 and the second dragging means 112 and used forreceiving beams emitted by the second radiation source 1522 andpenetrating through the inspected vehicle, wherein the second radiationsource 1522 is an X-ray beams accelerator or an X-ray beams machine.

As shown in FIG. 14, FIG. 15, FIG. 21 and FIG. 22, the vehicleinspection system further includes a transition means 235 arranged onthe separating section 113 between the first dragging means 111 and thesecond dragging means 112, wherein the transition means 235 is used forsupporting the vehicle when the vehicle moves from the first draggingmeans 111 to the second dragging means 112. See FIG. 2, FIG. 3, FIG. 4and FIG. 8, the transition means 235 can include a platform 12, anoverturning plate 13, a pedal 15 or other suitable supporting means orbrackets.

See FIG. 14, FIG. 15, FIG. 19, FIG. 21 and FIG. 22, the vehicleinspection system further includes a linear cantilever crane structurearranged near the ground of the inspection passage 101 and serving as afirst detector cantilever crane structure 116, wherein the firstdetector 1531 is arranged on the linear cantilever crane structure;moreover, at least a part of the linear cantilever crane structure isarranged near the ground of the separating section 113 between the firstdragging means 111 and the second dragging means 112. The linearcantilever crane structure can be entirely located below the ground ofthe inspection passage, or the linear cantilever crane structure can bearranged below the transition means 235.

Alternatively, see FIG. 14, FIG. 15, FIG. 19, FIG. 21 and FIG. 22, thevehicle inspection system further includes a U-shaped cantilever cranestructure serving as the first detector cantilever crane structure 116,wherein the U-shaped cantilever crane structure includes a substantiallyhorizontal cantilever crane structure 1161 and two substantiallyvertical cantilever crane structures 1162 extending upwards from the twoends of the substantially horizontal cantilever crane structure, thesubstantially horizontal cantilever crane structure is arranged near theground of the inspection passage 101, and the first detector 1531 isarranged on the substantially horizontal cantilever crane structure andthe substantially vertical cantilever crane structures; moreover, atleast a part of the substantially horizontal cantilever crane structureis arranged near the ground of the separating section 113 between thefirst dragging means 111 and the second dragging means 112. Thesubstantially horizontal cantilever crane structure can be arrangedbelow the transition means 235 or below the ground of the inspectionpassage. The substantially vertical cantilever crane structures can bevertical to the ground of the inspection passage and are located at thetwo sides of the inspection passage.

See FIG. 18, the vehicle inspection system further includes an L-shapedcantilever crane structure serving as a second detector cantilever crane126, wherein the L-shaped cantilever crane structure includes asubstantially horizontal cantilever crane structure and a substantiallyvertical cantilever crane structure extending upwards from the end ofthe substantially horizontal cantilever crane structure, thesubstantially horizontal cantilever crane structure is arranged near theground of the inspection passage 101, and the substantially horizontalcantilever crane structure can be arranged below the transition means235 or below the ground of the inspection passage. The second detector1532 is arranged on the substantially horizontal cantilever cranestructure and the substantially vertical cantilever crane structure;moreover, at least a part of the substantially horizontal cantilevercrane structure is arranged near the ground of the separating section113 between the first dragging means 111 and the second dragging means112. The substantially vertical cantilever crane structure can beperpendicular to the ground of the inspection passage and is located atone side of the inspection passage.

Alternatively, see FIG. 18, the vehicle inspection system furtherincludes an inverted L-shaped cantilever crane structure serving as thesecond detector cantilever crane 126, wherein the inverted L-shapedcantilever crane structure includes a substantially horizontalcantilever crane structure 1261 and a substantially vertical cantilevercrane structure 1262 extending downwards from the end of thesubstantially horizontal cantilever crane structure, the substantiallyhorizontal cantilever crane structure 1261 is arranged above theinspection passage 101, and the second detector 1532 is arranged on thesubstantially horizontal cantilever crane structure and thesubstantially vertical cantilever crane structure. The substantiallyhorizontal cantilever crane structure can be arranged above thetransition means 235. The substantially vertical cantilever cranestructure can be perpendicular to the ground of the inspection passageand is located at one side of the inspection passage.

According to some embodiments of the present invention, the firstdetector 1531 and the second detector 1532 can be arranged in othermanners, and the cantilever crane structure can also adopt other shapes.

In the vehicle inspection system according to the embodiment of thepresent invention, the vehicle can pass the inspection passage 101 undera first mode, a second mode or a third mode, under the first mode, thevehicle voluntarily passes the inspection passage 101, and theradiographic inspection system does not inspect the vehicle; under thesecond mode, the vehicle voluntarily passes the inspection passage 101,and the radiographic inspection system inspects the vehicle by adoptinga dosage lower than a first preset value, wherein the dosage of thefirst preset value can be a maximal dosage harmless to human body andcan also be a certain dosage below the maximal dosage; and under thethird mode, the vehicle dragging system drags the vehicle to pass theinspection passage 101, and the radiographic inspection system inspectsthe vehicle by adopting a dosage larger than or equal to a second presetvalue, the second preset value can be the same as or different from thefirst preset value, and preferably, the second preset value is largerthan the first preset value. Under the first mode and the second mode,the wheels on at least one side of the vehicle drive on the firstdragging means 111 and the second dragging means 112, or the vehicledrives on a road beside the first dragging means 111 and the seconddragging means 112.

As shown in FIG. 21 and FIG. 22, at least one of the first draggingmeans 111 and the second dragging means 112 includes two chains and apushing roller connected between the two chains to serve as a pushingelement 1141, wherein the pushing roller is used for pushing the wheelsof the vehicle, in order to drive the vehicle to advance to pass theinspection passage 101.

As shown in FIG. 14, FIG. 15 and FIG. 20, at least one of the firstdragging means 111 and the second dragging means 112 includes a platelink chain 114 (an example of a elongated traction element). The platelink chain 114 includes a projection serving as the pushing element1141, wherein the pushing element is used for pushing the wheels of thevehicle, in order to drive the vehicle to advance to pass the inspectionpassage 101.

According to the embodiment of the present invention, at least one ofthe first dragging means 111 and the second dragging means 112 drivesthe vehicle to advance to pass the inspection passage 101 through atleast one wheel of the vehicle. The pushing element pushes at least onewheel of the vehicle, in order to drive the vehicle to advance to passthe inspection passage 101.

As shown in FIG. 14, the vehicle inspection system further includes athird dragging means 110 substantially parallel to the first draggingmeans 111, for enabling the first dragging means 111 and the thirddragging means 110 to respectively drive the left and right wheels ofthe vehicle. The end of the third dragging means 110 adjacent to theseparating section 113 can be substantially aligned to the end of thefirst dragging means 111 adjacent to the separating section 113. Thethird dragging means 110 is an auxiliary dragging means.

As shown in FIG. 14, the vehicle inspection system according to theembodiment of the present invention can further include an entranceguide rail and a guide platform 105. The first dragging means 111 andthe second dragging means 112 can be used for dragging a single wheel ordouble wheels of the vehicle, in order to transfer the vehicle. When thevehicle drives on the first dragging means 111, the entrance guide railand the guide platform 105 correctly guide the vehicle travellingdirection and correct the deviation of the rear wheel.

As shown in FIG. 14, the third dragging means 110 is used for assistingin pushing the vehicle, when the vehicle transits from the firstdragging means 111 to the second dragging means 112.

As shown in FIG. 14, the vehicle inspection system according to theembodiment of the present invention can further include a wheel blockingmeans 103 located at the right side of the first dragging means 111, forblocking the rear wheel when the vehicle move towards a directionreverse to the travelling direction.

As shown in FIG. 16, FIG. 17, FIG. 18 and FIG. 19, the vehicleinspection system includes a top radiation source cabin 109 providedwith the first radiation source 1521, a side radiation source bin 122provided with the second radiation source 1522, the first detectorcantilever crane 116, the second detector cantilever crane 126, aradiogen detecting system 127, radiation shield walls 70, a computer,electric control equipment, imaging software and a sensor.

As shown in FIG. 16, FIG. 17, FIG. 18 and FIG. 19, the top radiationsource cabin 109 is located above the cantilever crane and is used forplacing the first radiation source 1521 and power distributionequipment; the side radiation source bin 122 is located on one side ofthe passage and is used for placing the second radiation source 1522 andpower distribution equipment.

As shown in FIG. 17, the vehicle inspection system according to thepresent invention can include a radiogen monitoring system, an automaticlicense plate identification system and a chassis camera system, whichare used for monitoring the existence of radiogen when performingradiation imaging inspection on the vehicle, identifying the licenseplate, automatically shooting the chassis and binding with the currentlygenerated vehicle image, for retrospect.

When the vehicle is scanned, the vehicle drives on the first draggingmeans 111, after the rear wheel of the vehicle drives on the firstdragging means 111, the system indicates the driver to stop through atraffic light, then the driver leaves the vehicle, after confirming thatthe driver leaves the vehicle, the first dragging means 111 is started,at this time, the first dragging means 111 pushes the wheels to movethrough the pushing element 1141, when the vehicle approaches to thebeam flow center 106 of the ray beam, the radiation source is controlledto begin to emit X rays, and the detector in a detector arm receives thebeams and converts the beams into necessary image data. The firstdragging means 111 continues to push the vehicle to advance andtransfers the vehicle to the second dragging means 112, the seconddragging means 112 continues to push the wheel to advance through thepushing element 1141, such that the entire vehicle passes the beam flowcenter 106, at this time, the system performs related inspection on thegenerated radiation image of the vehicle. When detecting that thevehicle completely passes the beam flow center, a radiation source beamemission stop command is sent. However, at this time, the seconddragging means 112 does not stop to transmitting the vehicle untilpushing the rear wheel of the vehicle away from the second draggingmeans 112, and the dragging system resets to the initial position towait for the next inspected vehicle to drive in.

In order to ensure the stable speed of the vehicle in the transferprocess, the third dragging means 110 will assist the first draggingmeans 111 to stably transfer the vehicle and stably transfer the vehicleonto the second dragging means 112.

The vehicle inspection system according to the present invention canoperate under a vehicle driving mode. Under the premise of the allowanceof the local law, radiation imaging under the mode can be achieved.After the system is ready, the driver is instructed to drive into thepassage through the traffic light, at this time, after the driver drivesthe vehicle to enter the inspection passage 101, the vehicle speed ismeasured through a speed sensor, in order to determine the beam emissionfrequency of the radiation sources 1521 and 1522 or the samplingfrequency of the detector. When the vehicle approaches to the beam flowcenter 106 of the ray beams of the radiation source 1521 or 1522, theradiation sources 1521 and 1522 are respectively controlled to emitbeams to scan the vehicle, in order to generate an X-ray beams image ofthe vehicle. After the vehicle leaves the beam flow center 106, thesystem sends a radiation source beam emission stop command, and theradiation sources stop emitting beams.

For an imaging system with an accelerator as the radiation source, thebeam emission frequency of the accelerator is determined through themeasured vehicle speed. For an imaging system with an X-ray beamsmachine as the radiation source, the sampling frequency of the detectoris determined through the measured vehicle speed.

According to the embodiment of the present invention, the vehicleinspection system can further include a vehicle identification systemused for identifying the type of the vehicle, in order to adopt acorresponding scanning inspection strategy according to the type of thevehicle. In addition, according to the embodiment of the presentinvention, the vehicle inspection system can further include a licenseplate identification system 129 for identifying the license plate numberof the vehicle. According to the embodiment of the present invention,the vehicle inspection system can further include a chassis camerasystem 128 for shooting the chassis of the vehicle. The chassis camerasystem is installed on the ground of the inspection passage 101 orbeneath the ground of the inspection passage 101.

Specifically, the vehicle inspection system according to the presentinvention can be provided with the radiogen detecting system and thelicense plate identification system. When the system performs theradiation imaging inspection on the vehicle, the radiogen detectingsystem 127 and the license plate identification system 129 installed atthe two sides of the inspection passage 101 and the chassis camerasystem 128 installed on the ground or beneath the ground of theinspection passage 101 simultaneously detect whether radiogen exists inthe vehicle 111, automatically identify the license plate of thevehicle, automatically shoot the chassis of the vehicle and associatethe processing result with the image generated by current radiationscanning, for retrospect.

Although the chain and the plate link chain serving as the elongatedtraction element are described, the elongated traction element in thepresent invention can be any suitable elongated traction element, forexample, a belt and the like.

Although some embodiments of the general idea of the patent have beenshown and illustrated, it will be understood by those of ordinaryskilled person in the art that, variations can be made on theseembodiments without departing from the principle and spirit of thegeneral idea of the patent, and the scope of the present invention islimited by the claims and their equivalents.

1. A vehicle inspection system, comprising: a radiation source; aninspection passage enabling a vehicle to pass; a dragging systemcomprising a first dragging means and a second dragging means, which aresequentially arranged along a vehicle dragging direction; in the vehicledragging direction, the first dragging means is arranged at the upstreamof the second dragging means, and a separating section is arrangedbetween the first dragging means and the second dragging means, so thatthe first dragging means is separated from the second dragging means bya preset distance in the vehicle dragging direction; and the first andsecond dragging means both include a supporting plate, an elongatedtraction element and a pushing element connected with the elongatedtraction element, the elongated traction elements of the first andsecond dragging means are continuous and integrated, thus the elongatedtraction elements and pushing elements extends on the separatingsection; the supporting plates of the first and second dragging meansare separated and two pieces type, and no supporting plate is providedon the separating section.
 2. A vehicle inspection system according toclaim 1 wherein said radiation source providing X-ray beams for scanninga vehicle and further comprising: a detector used for receiving theX-ray beams emitted from the radiation source; a scanning means framebeing arranged within the range of the inspection passage, the radiationsource is arranged at the top of the scanning means frame for scanningthe vehicle passing the inspection passage, and the detector is arrangedat a position opposite to the radiation source; at least a part of pathsof the beams of the radiation source passes through the separatingsection between the first dragging means and the second dragging means.3. The vehicle inspection system of claim 2, further comprising: thedragging means is arranged on the ground at one side within the range ofthe inspection passage, and is able to drag the vehicle which is drivinginto the inspection passage to pass the inspection passage.
 4. Thevehicle inspection system of claim 3, wherein the width of theinspection passage is arranged in such a manner that the vehicle is ableto pass the inspection passage by means of the dragging means, and thevehicle is also able to pass the inspection passage along the groundprovided with no dragging means.
 5. The vehicle inspection system ofclaim 2, further comprising: the radiation shield walls arranged at thetwo sides of the inspection passage a pedestrian passage arranged behindthe radiation shield walls, for enabling a driver to walk from astarting point where the vehicle drives into the inspection passage tothe destination where the vehicle is about to leave the inspectionpassage.
 6. The vehicle inspection system according to claim 1, whereinsaid dragging system is arranged in the inspection passage; and furthercomprising: a radiographic inspection system for inspecting a vehicle,wherein said radiation source is comprised in said radiographicinspection system, said radiation source for emitting beams ofpenetrating radiation and a detector for receiving the beams emitted bythe radiation source and penetrating through the inspected vehicle; atleast a part of paths of the beams of the radiographic inspection systempasses through the separating section between the first dragging meansand the second dragging means.
 7. The vehicle inspection system of claim6, wherein the pushing element is used for pushing wheels to move so asto drive the vehicle to advance.
 8. The vehicle inspection system ofclaim 6, wherein the radiation source is arranged above the inspectionpassage.
 9. The vehicle inspection system of claim 6, further comprisinga driving passage arranged in the inspection passage and used forenabling the vehicle to voluntarily pass, wherein the driving passage isarranged to be substantially parallel to the dragging means.
 10. Thevehicle inspection system of claim 6, further comprising a controller,wherein the controller corrects an acquired image of the inspectedvehicle according to a scanned image acquired by the vehicle inspectionsystem during no load of the dragging means, in order to remove theimage of the dragging means from the acquired image of the inspectedvehicle.
 11. The vehicle inspection system of claim 6, furthercomprising a controller, wherein the controller corrects an acquiredimage of the inspected vehicle according to a scanned image acquired bythe vehicle inspection system during no load of the dragging means, inorder to remove the image of at least one of the elongated tractionelement and the pushing element from the acquired image of the inspectedvehicle.
 12. The vehicle inspection system of claim 10, wherein thecontroller corrects the acquired image of the inspected vehicleaccording to the position relationship of the inspected vehicle and atleast one of the elongated traction element and the pushing elementalong the vehicle transfer direction, in order to remove the image of atleast one of the elongated traction element and the pushing element fromthe acquired image of the inspected vehicle.
 13. The vehicle inspectionsystem of claim 10, wherein the pushing element of the dragging meanscontacts the wheels of the vehicle and pushes the wheels, in order todetermine the position relationship of the inspected vehicle and atleast one of the elongated traction element and the pushing elementalong the vehicle transfer direction.
 14. The vehicle inspection systemof claim 10, further comprising: a position detecting means fordetecting whether the pushing element arrives at a preset position, andsending a signal to the controller when the pushing element pushing thewheels of the vehicle or the pushing element during no load of thedragging means arrives at the preset position, in order to start theradiographic inspection system to scan the vehicle or the no-loaddragging means.
 15. The vehicle inspection system of claim 14, whereinthe position detecting means is an optical transceiver, the opticaltransceiver is arranged at one side of the dragging means and emits alight beam towards one side of the dragging means, when the light beamirradiates a reflector at the end part of the pushing element, theoptical transceiver receives the light beam reflected by the reflectorat the end part of the pushing element, in order to determine that thepushing element arrives at the preset position.
 16. The vehicleinspection system of claim 6, wherein the first dragging means comprisesa first elongated traction element and a first pushing element connectedwith the first elongated traction element, and the first pushing elementis adapted to push the wheels to move so as to drive the vehicle toadvance; the second dragging means comprises a second elongated tractionelement and a second pushing element connected with the second elongatedtraction element, and the second pushing element is adapted to push thewheels to move so as to drive the vehicle to advance.
 17. The vehicleinspection system of claim 6, wherein the vehicle passes the inspectionpassage under a first mode, a second mode or a third mode, under thefirst mode, the vehicle voluntarily passes the inspection passage, andthe radiographic inspection system does not inspect the vehicle, underthe second mode, the vehicle voluntarily passes the inspection passage,and the radiographic inspection system inspects the vehicle by adoptinga dosage lower than a first preset value, and under the third mode, thedragging system drags the vehicle to pass the inspection passage, andthe radiographic inspection system inspects the vehicle by adopting adosage larger than or equal to a second preset value.
 18. The vehicleinspection system of claim 17, wherein under the first mode and thesecond mode, the wheels of at least one side of the vehicle drive on thefirst dragging means and the second dragging means or the vehicle driveson a road beside the first dragging means and the second dragging means.19. The vehicle inspection system of claim 17, wherein the pushingelement is adapted to push the wheels to move so as to drive the vehicleto advance, the vehicle inspection system further comprises a drivingpassage arranged in the inspection passage and used for enabling thevehicle to voluntarily pass, and the driving passage is arranged to besubstantially parallel to the dragging means, and under the first mode,the vehicle voluntarily passes the inspection passage.
 20. The vehicleinspection system of claim 6, wherein the elongated traction element isa chain or a plate link chain.